1. Field of the Invention
The present invention relates to a dust boot for a constant velocity universal joint.
2. Description of the Prior Art
The constant velocity universal joint is used to transmit the rotating power from one joint member to the other joint member so as to rotate at a constant velocity while allowing the above two joint members to freely deflect the axial center lines thereof from each other within a predetermined angle range.
When the above described constant velocity universal joint is used in a drive system or the like of a vehicle, the joint portion of the constant velocity universal joint is covered with a dust boot made of rubber. The dust boot generally has a deformable shape such as bellows. One open end of the dust boot is fit on the outer periphery of one joint member while the other open end thereof is fit on the outer periphery of the other joint member.
In the dust boot of this type, adjacent folds locally come in contact with one another when the constant velocity universal joint rotates at a high velocity with a large joint angle. As a result, wear occurs in the dust boot to shorten the life of the dust boot. In order to overcome the defect of the dust boot, wax is included in rubber material of the dust boot to smooth the outer surface of the dust boot. However, satisfactory effect to the above wear cannot be obtained.